Pyrazolone coupler for color photography



Patented Feb. 16, 1943 PYRAZOLONI COUPLER FOB COLOR PHOTOGRAPHY Henry1). Porter and ester, N. Y., assignors Arnold Weissberger, RochtoEastman Kodak Oompany. Rochester, N. Y., a corporation of New Jersey NoDrawing. Application November 14, 1941, Serial No. 419,113

111 Claims. (Ul- 95-8) This invention relates to photographic colorforming compounds and particularly to pyrazolone color forming couplercompounds.

The formation of colored photographic images by coupling the developmentproduct of aromatic amino developing agents with color forming orcoupling compounds is well known. In these processes the subtractiveprocess oi color formation is ordinarily used and the image dyes areintended to be of the complementarfprimary colors cyan or blue-green,magenta, and yellow. The couplers which produce the cyan dyes areusually phenols or naphthols, those producing the magenta dyes areordinarily pyrazolones or cyano acetyl compounds, and those producingthe yellow dyes are ordinarily compounds containing a. methylene grouphaving two carbonyl groups attached to it. The dyes produced by couplingare aaomethines. lndamines or indophenols depending upon the compositionof the coupler and of the developer.

We have now found a novel type of pyrazolone coupler which produces dyeshaving good absorption characteristics and good stability. Thesecouplers have the following general formula:

where a =a1m or aryi.

R'=H or alkyl. 1: =11 or acyl. The following examples illustratecompounds of this general class:

(1) N=O m Buy/Oi Q Kl ii i fl-anllino-fi-pyramolone m 10cma-ll-acetyianilino-fi-pymsolone 3-c-naphthylamlno-5-pyrazolone (and3-N-acetyl derivativel S-p-acetamlnoanilino-S-pyrazolone Br3-o-bromsnilino-5-pyrazoione (and 3-N-acetyl derivative)S-p-bromsnilino-S-pyrsdolone (and S-N-acetyl derivative)a-p-cyanoauilino-li-pyrasolone (and -8-N-acetyl derivative) N: O-NH NO]s-p-nitroanilino-fi-pyrazolone 3-p-iodoanilino-5-pyrazolone (andN-acetyl derivative) 3-N-m-valerylanilino-5-pyrazolcne3-p-tert.amylaniline-S-pyrazolone 3-p-dimethylaminoanilino-S-pyrazoloneN=CN*CI I 3-N-|benzoylanilino-5-pyrazolone course-Q BM l3-N-phenoxyacetylanilino-5-pyraaolone (17) COOHiO-GHI N=C-NO l IS-N-methoxyacetylanilino-fi-pyrazolone Bmethyi-ii-anilino B-WiaadloqeThe novel couplers of our invention are prepared by a modification. ofthe procedure described in Journal of the American Chemical Society,vol. 44,1924, page 1551 and vol. 48. 1028. page 2832. An isothiocyanateis condensed with ethylacetoacetate and the product is reacted withhydrazine hydrate or an alkyl-hydrazine according to the followinggeneral scheme:

sues CHJCOCHIOOICIHI mom comm. CHaCO-Ca CSNHR N=C-NHR R'N ms canoncnlcoma where By variation of the group attached to the amino nitrogenin the 3-position oi the pyrazolone ring couplers may be prepared whichhave the required solubility and other properties for use in variousmethods of color photography. Furthermore, the couplers can be acylatedby reaction with an organic acid anhydrlde or by an acid chloride in thepresence of a condensing agent suchas pyridine. This aflords anothermeans 01' varying the properties 01' the couplers.

Our couplers are designed for use in processes in which the coupler isincorporated in the developing solution such as those described inMarines and Godowsky U. S. Patent 2,113,329, granted April 5, 1938. orMarines, Godcwsky and Wilder U. S. Patent 2,252,718, granted August 19,1941. Certain oi the couplers or our inventicn may be incorporated insensitive emulsion layers for use in processes such as those describedin Fischer U. 8. Patent 1,055,155, granted March 4, 1913. Mannes andGodowsky U. S. applications Serial Nos. 314,688 and 314,689., flleo'January 19, 1940, and Jelley and Vittum U. S. application Serial No.371,612, flied December 26, 1940.

The following examples illustrate developing solutions containing thecouplers used according to our invention:

Example 1 A. 2 amino-5 diethylaminotoluene hydrochloride grams 2 Sodiumsulflte (anhydrous) ..do '2 Sodium carbonate (anhydrous) -do- 20Potassium bromide do 1 Water to -liter.- 1 B. 3-anilino-5-pyrazolone..grams 2 Sodium hydroxide (10% solution) .00... 10 B is added to A.

Example 2 A. nimethyl-p-phenylenediamine suli'ate -grams.. 3 Sodiumsulfite (anhydrous) -do 5 Sodium carbonate (anhydrous) do 20 Potassiumbromide do 2 Water to liter- 1 B. 3- n-amylanuno'-5-pyrazolone -grams 3Isopropyl alcohol cc B is added to A.

The foregoing examples refer to the addition oi the coupler compound tothe developing solution itself. The coupler may also be added to theemulsion layer provided that suitable means are used to prevent itsdiflusion in the case of multilayer coatings. Special dispersing agentsmay be used for incorporating the coupler compound in the emulsion andin certain cases the coupler may be absorbed or adsorbed to thesensitive salt or may be combined with the sensitive salt as a chemicalcombination.

In the development of exposed photographic silver halide emulsionlayers, using the couplers of our invention, any color forming developercontaining a primary amino group may he used. These include developershaving two primary amino groups as well as those having one of the aminogroups substituted or. having substituents in the ring such as alkylphenyienediamines and alkyl toluylene diamines. These compounds areusually used in the salt form such as the hydrochloride or the sulfatewhich are more stable than the amines themselves. Suitable compounds arediethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediaminehydrochloride, di'inethyl-p-phenylenediamine hydrochloride and2-amino-5-diethylaminotoluene hydrochloride. The p-amino phenols andtheir substitution products may also he used where the amino group isunsubstituted. All of these developers have an unsubstituted amino groupwhich enables the oxidation prodnets of the developer to couple with thecolor I forming compounds to form a dye image.

Our development process may be employed for the production of coloredphotographic images in layers of gelatin or other carriers, such ascollodion, organic esters of cellulose, or synthetic resins. The carriermay be supported by a transparent medium such as glass, a celluloseester or a non-transparent reflecting medium such as paper or an opaquecellulose ester. The sion may be coated as a single layer on the supportor as superposed layers on one or both sides oi the support. The supc md layers may be difl'erentially sensitized and a the dyes formed thereinby coupling may be bleached by an oxidizing agent such as chromic acidto colorless soluble compounds. The destruction of the dye in this waydoes not'destroy the silver image and a silver image may be developed,bleached and in which R is selected from the class consisting of allgvigroups and aryl g'roupsfl, R is selected irom the class consisting ofhydrogen and alkyl groups. and X is selected irom the class consistingoi hydrogen and acyl groups.

2. A color forming photographic developer comprising aprimary aromaticamino developing agent and. a coupler compound having the formula:

in which R is an aryl group and X is selected from the class consistingof hydrogen and acyl groups.

3. A color forming photographic developer comprising a primary aromaticamino developing agent and a coupler compound having the formula:

in which R is an aryl group.

4. A color forming photographic developer comprising a primary aromaticamino develophis agent and a coupler compound having the followingformula:

C- HI 5. A color forming photographic. developer comprising a primaryaromatic amino developing agent and a couplercompound having thefollowing formula:

6. A color forming photographic developer comprising a primary aromaticamino developing agent and a coupler compound having the followingformula:

7. The method of producing a magenta colored photographic image in agelatino-siiver halide emulsion layer which comprises exposing the layerand developing it with a primary aromatic amino developing agent in thepresence of a coupler compound having the formula:

matic amino developing agent in the presence of a. coupler compmmdhaving the formula:

inwhichnisanarylgroupandxisselected from the class consistlng ofhydrogen and soy] 8 9. A photographic emulsion for forming coloredimages a colloidal carrier containing a sensitive silver halide and acoupler compound having the iormula:

in which R is an aryl group and X is selected from the class consistingor hydrogen and acyl mum- mRY D. Foam 'ARNOLD Hbit

